In recent years, needs of flat panel displays have been growing with realization of advanced information society. Examples of flat panel displays include liquid crystal displays (LCDs), which are non-self-emitting displays; and plasma displays (PDP), inorganic electroluminescence (inorganic EL) displays, and organic electroluminescence (hereinafter also referred to as “organic EL” or “organic LED”) displays, which are self-emitting displays.
Among these flat panel displays, in particular, liquid crystal displays generally include an illumination device as a light source on the back surface of a transmission-type liquid crystal display element and the viewability of liquid crystal displays is improved by irradiating the liquid crystal display element from the back surface side.
In such a liquid crystal display, the light emitted from the light source is generally unpolarized light and 50% or more of the unpolarized light is absorbed by a polarizing plate disposed on the illumination-light-entering side of the liquid crystal display element. Thus, the efficiency of using light emitted from a light source is low. In color liquid crystal display apparatuses which include a white light source and a micro color filter that supports three primary colors or four primary colors within a display surface and in which color display is conducted by an additive color mixture, more than 70% of light is absorbed by the color filter and thus the efficiency of using light emitted from a light source is extremely low. Therefore, an increase in light utilization efficiency is highly demanded.
To solve the above problems, for example, there has been proposed a color display apparatus including a pair of transparent substrates disposed with a certain gap so that surfaces on which a transparent electrode is formed face each other, a liquid crystal layer sandwiched between the transparent substrates, a liquid crystal display element including voltage application means for applying a voltage corresponding to an image signal to matrix pixels formed by the transparent electrodes of the pair of transparent substrates, an illumination device that emits light in a blue region to a blue-green region, a wavelength-converting fluorescent body that emits red light by using, as excitation light, the light in a blue region to a blue-green region, a wavelength-converting fluorescent body that emits green light by using, as excitation light, the light in a blue region to a blue-green region, and a color filter that blocks light other than the light in a blue region to a blue-green region (e.g., refer to PTL 1).
There has been also proposed an organic EL element including an EL light-emitting element and a wavelength-converting fluorescent layer, in which, by disposing a reflective body on the side surfaces of the wavelength-converting fluorescent layer, light that travels toward the side surfaces can be efficiently output from the front (e.g., refer to PTL 2).